Husqvarna 343R, 345RX, 343F, 345FX, 345FXT manual

W orkshop manual 343R 345RX 343F 345FX 345FXT English[...]

1 W orkshop Manual Brushcutter , T rimmer Model 343R, 345RX, 343F , 345FX, 345FXT Contents General recommendations ___________________ 2 1. Starter __________________________________ 3 2. Electrical system _________________________ 7 3. Fuel system _____________________________ 15 4. Centrifugal clutch ________________________ 31 5. Angle gear ____[...]

2 502 51 03-01 General r ecommendations ! ! ! ! ! ! Remember: Never start the engine without the clutch and clutch drum mounted. Do not grasp hot elements such as the muffler or the clutch before they have cooled sufficiently to avoid burn injuries. Avoid getting petrol on you skin or in your mouth. Use protective cream on your hands. This lowers t[...]

3 1 1. Contents Dismantling _________________________________ 4 Assembly __________________________________ 5 Replacing the drive dogs ______________________ 6 Star ter[...]

4 1 502 50 18-01 Star ter W ARNING! Protective glasses should be worn when working on the starter to avoid injury to the eyes if, for some reason, the return spring should fly out. ! Remove the bolt in the centre of the starter pulley and remove the starter pulley . Remove the bolt in the centre of the starter pulley . Lift the starter pulley caref[...]

5 1 ! Star ter Assembly Clean requisite parts and assemble in the reverse order as set out for disman- tling. Assembly Clean all components before assembly: Change return springs, starter pulley and starter cord as needed. NOTE! Be careful when opening the packaging with the return spring so that the spring does not fly out. Attach the spring casse[...]

6 1 Star ter Replacing the drive dogs See chapter 2 Ignition system. Replacing the drive dogs See chapter 2 Ignition system. T ighten the return spring. Check the spring tension. T ighten the return spring. Lift up the starter cord when the return spring is completely loose and the cord pulled out completely . Then turn the starter pulley anti- clo[...]

7 2 . 2 Electrical system Contents Checking the ignition spark ____________________ 8 Replacing the spark plug cover ________________ 10 Dismantling ________________________________ 11 Drive dogs _________________________________ 1 2 Assembly _________________________________ 12 Heated handles _____________________________ 12[...]

8 2 502 71 13-01 502 51 91-01 Electrical system The engine is equipped with an electronic ignition system completel y without moving parts. Conse- quently , a faulty component cannot be repaired, b ut must be replaced by a ne w component. The spark in an electronic ignition system has a very short burn time and can theref ore be interpreted as weak[...]

9 2 Electrical system Still no spark? Check the ignition cable’s connection to the spark plug cover . Still no spark? Check the spark plug connection. Remove the spark plug cover and make sure the ignition cable is not damaged. Remove a segment of cable if required to get sufficient contact at the connec- tion coil. If no spark occurs, disconnect[...]

10 2 502 50 06-01 502 51 34-02 0.3 Electrical system Replacing the spark plug cover 1 . Insert the ignition cable through the spark plug cover . 2. Make a hole in the ignition cable for the ignition coil. Replacing the spark plug cover 1. Lubricate the ignition cable with a little grease and thread it through the spark plug cover . 2. Cut off a bit[...]

11 2 502 51 94-01 502 54 15-01 502 50 18-01 Electrical system Remove the nut holding the flywheel. Remove the flywheel. Remove the nut holding the flywheel. Remove the flywheel from the crank- shaft using punch no. 502 51 94-01. Leave a gap of approx. 2 mm between the punch and the flywheel. Gently knock the punch with a hammer while holding the fl[...]

12 2 502 51 34-02 0.3 502 50 18-01 502 50 18-01 Assembly Check the key groove in the crankshaft and key in the flywheel. If damaged the components must be replaced. Attach the ignition module and then the flywheel. Check the air gap, see page 9. Assembly Check that the key groove in the crankshaft is not damaged. If it is, the crankshaft must be re[...]

13 2 Electrical system Separate the contacts (A-A) and (B-B). Then extend the cables (A) and (B) with approx. 90 cm long steel wires attached to the contacts. Separate the contacts (A-A) and (B-B). Then extend the cables (A) and (B) with approx. 90 cm long steel wires attached to the contacts. This is to make it easier to draw the cables to the new[...]

14 2 Electrical system[...]

15 3 3. Contents Air filter ___________________________________ 16 T ank venting _______________________________ 1 7 Fuel filter __________________________________ 1 7 Fuel pump _________________________________ 18 Carburettor ________________________________ 18 Assembly _________________________________ 24 Carburettor settings ____________________[...]

16 3 Fuel system In addition to the fuel tank and carb urettor , the fuel system consists of the air filter , fuel filter and tank venting. All these components interact so that the engine receives the optimal mixture of fuel and air to make it as efficient as possible. V ery small deviations in the carb urettor setting or a bloc ked air filter hav[...]

17 3 531 03 06-23 531 00 60-76 502 50 83-01 T ank venting Check that the tank venting valve works correctly . Replace the fuel cap if the valve is faulty . T ank venting T ank venting takes place through the fuel cap and needs to be functional for the engine to work. • Remove the fuel hose from the carburettor and empty the fuel from the tank. ?[...]

18 3 505 38 13-08 502 50 18-01 Carburettor Dismantling Blow clean the carburettor compartment. Loosen the bolts (A) and remove the nuts (B). Remove the fuel hose (C) and fold the filter holder aside. Carburettor Dismantling 1. Remove the carburettor cover and blow the carburettor compartment clean with compressed air . 2. Loosen the bolts (A). 3. R[...]

19 3 Fuel system Remove the throttle cable and fuel hose from the carburettor . Remove the carburettor . Remove the throttle cable from the carburettor ’s lever arm using flat nose pliers. Pull off the fuel hose and remove the carburettor . Tip! Open the fuel cap to avoid fuel spillage caused by any excess pressure. Attach the fuel hose to the re[...]

20 3 531 03 06-23 Fuel system Pressure test the metering unit. Connect pressure tester 531 03 06-23 to the fuel hose nipple. Lower the carburettor in a vessel with petrol in order to discover any leaks more easily . T est the pressure at 50 kPa. No leakage is permitted. Dismantling the carburettor Remove the control diaphragm and check for damage. [...]

21 3 Fuel system Check the needle valve and the lever arm for damage or wear . Replace damaged components with new ones. Check the needle valve for damage on the tip and in the lever arm groove. Check the lever arm for damage to the groove for the needle valve and wear on the mounting points towards the control diaphragm. Replace damaged components[...]

22 3 Fuel system Dismantle the main jet (A) and the plug (B). Press out the main jet (A) with a suitable punch. Remove the plug (B). Carefully drill a small hole (Ø 2 mm) in the plug and pry it up with a pointed object. Check valves and dampers for wear . Replace if required. Remove the valves and dampers. If these components are worn, idling is d[...]

23 3 Fuel system Assembling the carburettor • Blow all channels in the carburettor compartment clean • Mount a new plug. Use a suitable punch to get a completely tight seal. • Press in a new main jet. • Mount the valves and dampers. Tip! Any numbers on the valves should be able to be read from the outside. Replace the fuel screen if it is d[...]

24 3 531 03 06-23 Fuel system Check that the carburettor is sealed. No leakage is permitted at 50 kPa. Connect pressure tester 531 03 06-23 to the fuel intake on the carburettor . Pump up the pressure to 50 kPa. Lower the carburettor in a vessel with petrol in order to discover any leaks more easily . No leakage is permitted. Attach the control dia[...]

25 3 T Fuel system The needles must be correctly adjusted in order for the engine to give maximum power at different speeds, run steadily while idling and to react quickly when accelerating. The setting of the carburettor can vary a little depending on the humidity , tempera- ture and air pressure. L = Low speed needle H = High speed needle T = Idl[...]

26 3 502 71 14-01 501 60 02-03 Fuel system Correctly adjusted carburettor A correctly adjusted carburettor means that the engine accelerates without hesitation and it “splatters” a little at full throttle. • A too lean adjusted L-needle can cause starting difficulties and poor acceleration. • A too lean adjusted H-needle results in lower po[...]

27 531 00 48-63 531 03 03-98 502 50 18-01 3 Carburettor needles with Zama “caps”. Carburettor adjustment 345RX/FX Adjusting the L-needle 1. Mount the T rimmy Fix (4 wires) and use 3.3 mm smooth cord. The cord length should be 160 mm measured from the end of the cord to the cord bushing on the trimmer head. 2. Run the engine warm for about 5 min[...]

28 3 G Fuel system Remove the bolt (A) and remove the throttle from the handle. Remove bolts (B) and (C). Separate the halves of the throttle. Remove the bolt (A) that attaches the throttle to the handle. Be careful not to lose the nut. Remove the throttle and remove bolts (B) and (C). Carefully separate the two halves of the throttle. Check for we[...]

29 3 Disassemble the throttle control (A), the lock to prevent accidental throttle operation (B), the start throttle lock (C) and the throttle stop (D) in order to check if replacement is necessary . The stop switch can also be disassem- bled now , and replaced if necessary . Use a screwdriver to press the stop switch’s wing locks (E). Tip! Reass[...]

30[...]

31 4 4. Contents Dismantling ________________________________ 30 Assembly _________________________________ 32 Clutch drum _______________________________ 32 Centrifugal clutch[...]

32 4 502 21 58-01 Centrifugal clutch The centrifugal c lutch has the task of transferring the power fr om the engine to the cutting equipment’ s drive axle. As the name implies, it works accor ding to a centrifugal principle. This means the c lutch’ s friction shoes are thrown out- wards to wards the c lutch drum at a certain engine speed. When[...]

33 4 502 54 15-01 Centrifugal clutch Dismantle the clutch from the crank- shaft. Replace the spark plug with piston stop no. 502 54 15-01. Move the engine body to the side so that the clutch becomes accessible. Unscrew the clutch from the crankshaft. Remove the 3 bolts and separate the clutch. Fix the clutch in a vice and remove the 3 bolts. Lift o[...]

34 4 502 52 16-02 502 11 46-03 Centrifugal clutch Assembly T emporarily place the clutch shoes on the driving disc and loosely tighten the bolts. Pry out the shoes and hook one spring to each shoe from underneath. Assembly T emporarily place the clutch shoes on the driving disc and loosely tighten the bolts. Pry out the shoes and hook one spring to[...]

35 4 505 38 17-09 Centrifugal clutch Change the bearings in the clutch housing if necessary . Change the bearings in the clutch housing if necessary . Remove the circlip and push out the bearings with a suitable punch and hammer . Dismantling is easier if the clutch housing is heated to about 1 10°C. Assemble in the reverse order as set out for di[...]

36[...]

37 5 5. Contents Dismantling ________________________________ 36 Assembly _________________________________ 37 Shaft _____________________________________ 38 Angle gear[...]

38 5 Angle gear Dismantling Remove the cutting equipment and guard. Then loosen the bolts holding the angle gear against the shaft. Remove the angle gear from the shaft. Dismantling First remove the cutting equipment (saw blade, trimmer etc.) and guard. Then loosen the bolts holding the angle gear against the shaft. Remove the angle gear from the s[...]

39 5 502 50 65-01 503 97 64-01 Angle gear Remove the lubricant top-up plug. W arm the gearbox and knock it against a wooden block so that the input axle falls out. Remove the lubricant top-up plug and warm the entire gearbox using a hot air gun to about 150°C. Knock the gearbox against a wooden block so that the input axle and bearing fall out. NO[...]

40 5 503 80 17-01 Angle gear Shaft The shaft contains a drive axle guide that is easily replaced. It can be dismantled once the plastic sleeve (B) has been removed. Centre the axle control in the shaft when a new one is fitted. Fit a new O-ring to ensure a good seal. Shaft The shaft contains a long plastic guide to prevent vibrations in the drive a[...]

41 6 6. Contents Dismantling ________________________________ 42 Decompression valve ________________________ 4 3 Inlet manifold ______________________________ 44 Cleaning, inspection _________________________ 44 Assembly _________________________________ 44 Analysis and actions _________________________ 45 Service tips ____________________________[...]

42 6 502 50 18-01 A Cylinder and piston The cylinder and the piston are tw o of the compo- nents exposed to most strain in the engine. They must withstand, for e xample, high speeds, large tempera- ture swings and high pressure. Moreover , they m ust be resistant to wear . Despite these tough w orking conditions, major piston and cylinder failure i[...]

43 531 03 06-23 502 52 42-01 6 Dismantle the piston. Push the gudgeon pin from the piston using punch 502 52 42-01. If the pin is too tight, carefully warm the piston. Decompression valve Dismantle the decompression valve. Decompression valve Remove the bolt (A) and the hose (B) that connect the decompression valve to the nipple on the cylinder . U[...]

44 6 Cleaning, inspection After dismantling, clean the individual components: 1. Scrape carbon deposits from the top of the piston. 2. Scrape carbon deposits from the cylinder ’s combustion chamber . 3. Scrape carbon deposits from the cylinder ’s exhaust port. 4. W ash all the components. 5. Inspect the different components for damage and wear [...]

45 6 502 50 70-01 Cylinder and piston Use a new gasket and fit the cylinder . Make sure that the inlet manifold is correctly connected to the sleeve coupling on the cylinder and that the impulse nipple sits right. Place a new cylinder pedestal gasket on the cylinder . Lubricate the piston and the inlet manifold on the cylinder with a few drops of e[...]

46 6 Cylinder and piston Action: Change to a fuel with the correct oil mixture. Change to a higher octane petrol. Replace damaged parts. Replace leaking gaskets and shaft seals. Clean the cooling fins and air intake. Clean or replace the spark arrestor mesh. Cause: • Incorrect oil mixture in the fuel. • T oo low octane fuel. • Air leaks. Crac[...]

47 6 Cylinder and piston Exhaust side damaged by a br oken piston ring. The piston ring parts damage the top section and cause score marks. Piston damage caused by a too high engine speed. T ypical damage associated with a too high engine speed includes broken piston rings, broken circlip on the gudgeon pin, faulty bearings or that the guide pin fo[...]

48 6 Cylinder and piston Small score marks and a matt, grey surface on the piston’ s inlet side caused by fine dust particles. Cause: • Faulty air filter . Small dust particles pass through the filter . • The filter is worn out due to too much cleaning, whereby small holes have appeared in the material. • Unsuitable filter maintenance, such[...]

49 6 Cylinder and piston Cause: • Air filter damaged or missing. • Parts from the carburettor or intake system have come loose and entered the engine. Action: Fit a new air filter . Regular service and inspection. Extensive damage to the lower part of the piston’ s inlet side . Service tips Defect: Broken cooling fins, damaged threads or shea[...]

50 6 Cylinder and piston Wear tolerances When the surface coating is worn and aluminium appear s. Max. 1.0 mm with the piston ring inserted in the lower part of the cylinder . Max. 1.6 mm. Clean the groove before chec king the measure- ment. Max. 0.15 mm. Clean the groove before c hecking the measure- ment. Piston ring play Piston ring groove Pisto[...]

51 7 7. Contents Dismantling ________________________________ 52 Inspecting the crankshaft _____________________ 54 Assembly _________________________________ 55 Leakage testing the crankcase _________________ 56 Crankshaft and crankcase[...]

52 7 502 50 18-01 Crankshaft and crankcase The crankshaft is journalled in the crankcase on heavy-duty ball bearings. In addition to the journalling point f or the crankshaft, the crankcase acts as a scavenging pump f or the fuel/air mixture when this is “suc ked” from the carb urettor and is forced into the cylinder’ s combustion c hamber . [...]

53 7 502 52 39-01 505 38 17-09 Crankshaft and crankcase Separate the crankcase halves. Fit tool 502 52 39-01 to the clutch side of the crankcase as illustrated. Separate the crankcase halves. Fit tool 502 52 39-01 as illustrated. Push out the crankshaft from the crankcase half. Push out the crankshaft from the crankcase half. Remove the bearing and[...]

54 7 Check the crank bearing. Check the crank bearing. The connect- ing rod shall not have any radial play (up and down). It should, however , have axial play , in order to ensure good lubrication of the crank bearing among other things. Inspect the crankshaft bearing and sealing rings. Check for wear in the crankshaft bearing and sealing rings. Cl[...]

55 7 502 50 30-19 502 50 30-19 Crankshaft and crankcase Check that the there is no play in the fill-out plates around the crank disks (applies to models F X /F XT , R X ). Check that the there is no play in the fill-out plates around the crank disks (applies to models F X /F XT , R X ). Assembly Mount the bearings in the crankcase halves. Assembly [...]

56 7 505 38 17-09 502 54 11-02 503 84 40-01 Crankshaft and crankcase Leakage testing the crankcase Fit the two sealing plates (A) and the pressure test nipple (B). Leakage testing the crankcase Remove the throttle cable and air filter holder from the carburettor . Fit a sealing plate (A) 502 54 1 1-02 between the carburettor and the distance piece [...]

57 7 531 03 06-23 503 55 22-01 Crankshaft and crankcase Fit plug 503 55 22-01 instead of the decompression valve. Connect meter 531 03 06-23 and check for leakage. Fit plug 503 55 22-01 instead of the decompression valve. Connect meter 531 03 06-23 to the nipple and pump up a pressure of 50 kPa (0.5 kp/cm 2 ) in the crankcase. Max. permitted leakag[...]

58[...]

59 8 . Tools Contents Starter __________________________________ 60 Electrical system __________________________ 6 0 Fuel system _____________________________ 60 Centrifugal clutch _________________________ 60 Angle gear ______________________________ 61 Cylinder and piston ________________________ 6 1 Crankshaft and crankcase __________________ 61[...]

60 531 00 48-63 531 03 03-98 502 51 91-01 502 71 13-01 502 51 34-02 0.3 502 50 06-01 502 54 15-01 502 51 94-01 531 00 60-76 502 50 83-01 501 60 02-03 502 21 58-01 502 54 15-01 502 52 16-02 502 1 1 46-03 505 38 17-09 502 50 18-01 502 50 18-01 502 50 18-01 505 38 13-08 Electrical system Fuel system Centrifugal clutch Starter Fuel system List of tools[...]

61 502 52 39-01 505 38 17-09 502 50 30-19 502 54 1 1-02 503 84 40-01 503 55 22-01 502 51 03-01 502 71 14-01 502 50 65-01 503 97 64-01 503 80 17-01 502 52 42-01 531 03 06-23 502 50 70-01 502 50 18-01 505 69 85-70 101 64 23-48 503 26 70-01 502 50 18-01 Angle gear Cylinder and piston Crankshaft and crankcase Workshop equipment List of tools 8[...]

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